RE: [RFC PATCH v2 4/5] scsi: ufs: L2P map management for HPB read

Avri Altman
2020-06-17T11:44:08Z

> +
> +static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu *hpb)
> +{
> + struct ufshpb_map_ctx *mctx;
> + int i, j;
> +
> + mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
> + if (!mctx)
> + return NULL;
So you use ufshpb_host_map_kbytes as the min_nr in your mempool_create,
But you know that you need max_lru_active_cnt x srgns_per_rgn such mapping context elements.
So you are
a) failing to provide the slab allocator an information that you already have, and
b) selecting from a finite pool will assure that you'll never exceed max-active-regions,
even if some corner case fails your logic.